Process for reducing the viscosity characteristics of nitrocellulosic materials



- terial, suc

' line earth metals.

Patented Sept. 7, 1926.

u iT-Eo "STA rm, or aocnnsrna, rnocnss non nnnucme 'rnn VISC Io Drawing.

This invention relates to processes for re-.

ES PATENT OFFICE. 1

ducing the viscosity characteristics of nitro- One cellulosic materials.

object of the invention is'to provide a safe, simple and inexpensive process for treatlng such materials in order to lower the teristics. Another object to provide a viscosity characof the invention is process which can be operated at atmosphenc pressure and at room temperature without'the trouble and expense of .pressure -vessels or heating will hereinafter appear.

Other objects operations.

In the manufacture of nitrocellulose lacsuch as those used quers,

it is desirable to example, erties of into such lacquers.

for spraying, for modify the prop nitrocellulose before it is made up The ordinary nitrocelluloses have high viscosity characteristics when made up into the usual lacquer solutions.

Their viscosity characteristics should, therefore, be lowered so that they can .be made into highly concentrated yet easily flowable or sprayable solutions. Moreover,

the ability to reduce the "viscosity characteristics of nitrocellulose makes available for use in lacquers, lar e istics 'of nitrocellulose ma amounts of waste or'scrap maas pyroxylin waste and photoviscosity characterhe reduced by acting thereon with'a so ution of one or more of the hypochlorites The process is preferab of alkali or alkacarried out at room temperature and atmospheric pressure although the action is speeded up if the bath is warm.

In the preferred form of my invention I select calcium hypochlorite, Ca(ClO) and employ a saturated solution of it.

This is a relatively inexpensive material and it is easy to obtaina workable concentration by employing a saturated solution without danger of getting the bath too strong.

While I vention b 'understoo cellulose, say in the form 0 shall describe one form of my in-' way of illustration, it will be' that the invention is not limited tothe details of this example, dicated in the appended claims.

except as in- 1 The nitrof pyroxylin waste osirx ommacraars'rrcs or nrraocELLuLosIc MA EnIALs.

Application filed February 25, 1925. Serial No. 11,602.-

or film scrap from which the gelatinous coat-.

ings have been removed, and also preferably in comminuted form, is immersed in a saturated aqueous solution of calcium hypochlorite at room temperature and atmospheric pressure.

or. ROCHESTER, NEW YORK, assrenonmo EASTMAN KODAK cou- NEW ronx, A coaronnrron or NEW YORK.

The duration of the treatment is preferably determined by test. From time to time representative samples of the material are taken out of the bath, washed, dried, dissolved, and the viscosity of the solutions measured. The action may vary from one day to more than a week according to the desired amount of the reduction in viscosity characteristics, and according to the highness of the viscosity characteristics atthe start of the treatment. The nitrocellulosic material may contain, along with the nitrocellulose in solid colloidized form, high-boiling compounds or softeners, such as camphor, butyl alcohol, etc. The presence of such compounds does not interfere with the process but, in fact, tends to facilitate it and reduce the time of operation.

Having thus described my invention, what I claimas new and desire to secure by Letters Patent is:

1. The process of treating nitrocellulosic material which comprises acting thereon with a'bath of hypochlorite until the viscosity characteristics of the nitrocellulose are reduced thereby.

2. The process of treating colloidiz'ed nitrocellulose which comprises acting thereon with an a ueous solution of a hypochlorite of an a kaline earth metal until the viscosity characteristics of the nitrocellulose are reduced thereby.

3. The process of treating nitrocellulosic material which comprises acting thereon with an aqueous saturated solution of calcium hypochlorite until the viscosit characteristics of the nitrocellulose are owered thereby.

4. The process of treating solid colloidized nitrocellulose associated with high-boiling organic compounds which comprises immersing-such material, while in comminuted form, in an aqueous bath of hypochlorite until the viscosity characteristics of the temperature until the Viscosity characternitrocellulose are reduced thereby. istics of the nitrocellulose in the scrap are 5. The process of treating film scrap in reduced thereby. comminuted form and substantially free Signed at Rochester, New York, this 11th 5 from gelatinous coatings, which comprises day of February 1925.

immersing said scrap in a saturated aqueous solution of calcium hypochlorite at room VICTOR E. KIMMEL. 

